In February 2010, Bynes was cast alongside Owen Wilson, Jenna Fischer and Jason Sudeikis in the raunchy Farrelly brothers comedy Hall Pass. The New Line Cinema film revolved around unhappy husbands whose wives allow them to have sex with other women for one week. Bynes was cast as Paige, a provocative 21-year-old babysitter interested in Wilson's character.

Shooting began in Atlanta in early 2010, and according to a source involved in the production, Bynes was problematic from the start: On the first day of filming, it became clear that she didn't know her lines and was not gelling with the cast. Her behavior was described as "out of nowhere" by this insider, who says that Bynes admitted she was going through a rough breakup (she had been linked to rapper-actor Kid Cudi at the time). The filmmakers are said to have determined that the remainder of the shoot would be a struggle with Bynes on board, so they hired actress Alexandra Daddario to replace her. (Another source says that Bynes' departure from Hall Pass stemmed from a misunderstanding over the size of her role. Peter and Bobby Farrelly declined comment.)

Representatives for Bynes denied she was fired, and the actress tweeted that she left because of scheduling issues, but the damage was done. Observers now believe the Hall Pass debacle initiated her downward spiral. After all, one source says, Bynes had longed for a chance to prove she could handle an adult role. And after finally getting such a shot, she fumbled it. (THR attempted to contact Bynes through her former representatives but was rebuffed.)

After her departure from Hall Pass, Bynes raised eyebrows on Twitter with suggestive posts about her sexual proclivities. "It's amaziing how good it feels when someone knows how to love your body! I am having withdrawals from a certain guy lol :)" she tweeted in April 2010. "So turns out i prefer chocolate over vanilla. interesting." (Her Twitter account has since been scrubbed of all tweets and remains idle with about 300,000 followers.) In June 2010, she again took to Twitter, this time to announce her retirement: "Being an actress isn't as fun as it may seem."

After retiring, Bynes largely disappeared and wouldn't register with the public until her April run-ins with the law, which were only the beginning of a nearly six-month string of embarrassing incidents.

A source with insight into the actress' thinking says that part of the problem is Bynes doesn't believe she needs help or guidance. "She doesn't think she needs crisis management or professional help -- she says she is good, she is fine," this person says. Yet it isn't clear who was advising Bynes during her implosion this year. The actress' former representatives won't say why or exactly when they stopped working with her, though sources say that the actress' relationships with CAA and Feldman ended in 2010 when she announced her retirement. Feldman, who also is Lohan's attorney, declined comment for this story; Raubvogel, Bynes' former publicist, also declined comment.

Longtime publicist Nancy Kane, who has represented Roseanne, Matt LeBlanc and Kirstie Alley, says actors' representatives are sometimes put in a difficult position. "I'd be lying if I said in 20 years I hadn't seen a team enable. But at the end of the day, if you are professional, it's a business, and enabling someone's bad behavior -- it'll come out." In Bynes' case, a Daily Beast story said that before parting ways, her CAA agents staged an unsuccessful "please-get-help talk with her." (CAA declined comment.)

That wouldn't be the first failed effort to confront a young star about her personal troubles. A talent agent who once worked with a team that represented Lohan said that during the actress' mid-2000s ascent, her agency grew worried about her increasingly unruly behavior. A discussion was had about whether it was the agents' responsibility to intervene, and this person says that many of those in the room felt that Lohan's personal life and the attendant drama was "an ugly mess and not worth the risk of getting involved." However, a senior agent decided to bring in Lohan and her mother, Dina, for a frank discussion about the actress' behavior. "We had a real conversation about how 'you need help,' " recalls this person. One week later, Lohan fired her agents and signed with another company. "I was pretty proud of the people who had said we should do something. But the people who argued we shouldn't have said anything said: 'What the f--? Look what happened.' "

Of course, many executives believe that reining in wayward child actors is a responsibility of parents. To that end, Disney Channel, for example, offers a seminar called Talent 101, which features security experts, psychologists, showrunners and life coaches, and aims to help child actors and parents learn how to navigate the tricky waters of fame. "But at the end of the day, it's the parents who really have to be parents," Gary Marsh, president of Disney Channels Worldwide, told THR in a June interview. "We give them the tools they might need, but the network is not responsible for raising their children."

There is a precedent of parents stepping in when their A-list children are in crisis: Some observers invoked Britney Spears' placement under the conservatorship of her father after a 2008 meltdown and questioned whether Bynes' troubles also could be tied to psychological issues.

It's not clear what role Bynes' parents play in managing her personal or professional life; Rick Bynes served as her manager until about 2007, according to a source, but could not be reached for comment.

With the looming court dates, there is little talk of Bynes staging a Hollywood comeback -- particularly because she hasn't said this interests her. But if Bynes changed her mind, a comeback would be tough, says Kane. "Once you have a photo of a pipe in your mouth in a car, you can't un-ring that bell," she says. "It would be hard to see Amanda Bynes as a rosy-faced ingenue ever again. She's crossed a line." Still, such stars as Robert Downey Jr. and Barrymore have bounced back from well-documented substance abuse issues -- and Lohan is in the midst of yet another attempted comeback of her own -- proving that Hollywood can be forgiving of such indiscretions.

If Bynes never makes another movie, her final film will be the 2010 Screen Gems comedy Easy A. No one connected to the project would discuss her comportment on the Ojai, Calif., set, though there were no reports of trouble. The film received strong reviews and ultimately helped launch then-21-year-old Emma Stone's career. In Easy A, which grossed $75 million worldwide, Bynes was cast in a familiar role: a high school drama queen.

It couldn't have been easy for Bynes to stand by and watch the Hollywood machinery align to catapult Stone to stardom, much in the same way that it decided Lohan was the child star to place on the fast track instead of her.